HUMPTY DUMPTY - TEACHER INFORMATION

Forensic Science Project

This assessment activity provides students with multiple opportunities to demonstrate their skills developed in the previous activities and use the data collected from the tests to draw appropriate conclusions. The emphasis in this performance task is not on one correct answer, but the process the students use to get to their answer and how they provide evidence to support their answer. To assist the students in organizing their data and thoughts a table is provided. To arrive at a guilty suspect, students will have to use all the evidence provided to determine which suspect had motive and opportunity to commit the crime. Note that each suspect has the motive and opportunity. What determines the guilty suspect is the results from the evidence collected at the crime scene. This is advantageous for future classes. One year Mr EG White could be guilty and the next year it could be Ms Yolk simply by shifting the evidence around. For this task the guilty suspect is, in fact, Mr EG White.

There is no set order for these tasks. Students can choose to examine the evidence in any order they wish. As a result, all evidence must be available at the start. Your pre-assessment tasks include:

Fingerprints

• At the crime scene an arch fingerprint was found. Ms Yolk and Mr Chaleza both have a least one finger that is arch. Mr EG White doesn't have an arch, but he is also a glove salesman, so he may have had gloves on. You will need to add fingerprints for each suspect and one for the crime scene.

Fiber/Hair Analysis

• The hair found at the crime scene was light brown. Only Mr White had brown hair. The others were any other colour. Making permanent slides of the hair is an efficient and effective method for ensuring all students see the same evidence. It also allow for the slides to be reused in the future

Pen Analysis - Paper Chromatography

• The pen found at the crime scene is a non-water soluble pen. As a result the colours will not separate out in a chromatogram. Both Mr White and Mr Chaleza have non-water soluble pens. Ms Yolk has a water soluble pen. You will need to have small pieces of paper for each suspect and the crime scene with some pen mark on each for this activity.

Chemical Detection - White Powder Analysis

• At the crime scene baking soda and sugar are in the white powder. Ms Yolk has a white powder of baking soda and salt. Mr Chaleza has a sugar and starch powder and Mr White is baking soda and sugar. Students will have to perform all seven tests to confirm the composition of the four powders.

DNA Fingerprints

• There is no match between the DNA samples found at the crime scene and the suspects. You will need to provide 10 -15 barcodes representing DNA samples from the crime scene and a bar code for each suspect.

The information from above is summarized in the following table.

As mentioned earlier, Mr EG White is the guilty suspect. Not only did his hair, pen, white and white powder match the crime scene, he had motive and opportunity. His motive was that he owed Mr Dumpty money and since his whereabouts that afternoon are unknown, he had the opportunity. While the other two suspects had motive and opportunity, they did not have as much evidence against them as Mr White.

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